Field of the Invention
The present invention relates to a discharge valve device, a reservoir tank device, and a flush toilet.
Description of Related Art
For some time, flush toilets have been known in which a toilet main body is flushed by flush water stored in a reservoir tank device. A discharge valve device is used in this reservoir tank device; as an example of such a discharge valve device, a discharge valve device is used in which a discharge port is opened and closed by raising and lowering a valve body in the vertical direction relative to a discharge port in the flush water tank.
In a known such discharge valve device, a float for applying buoyancy to a valve body is formed as an integral piece with a valve body (e.g., see Patent Document 1 (U.S. Pat. No. 8,079,095)).
However, in a discharge valve device such as that in Patent Document 1, the valve body discharge port release time is essentially fixed at all times, so only a predefined amount of flush water can be supplied to the toilet main body. Because the amount of flush water varies with toilet type, a discharge valve device cannot be applied to other types of toilet.
A discharge valve device capable of adapting to differing toilet types by adjusting the amount of flush water is therefore desired. However, the amount of flush water differs according to toilet type. Therefore when applying such discharge valve devices to a toilet, it is preferable for the flush water amount not to be easily changed by a user or by external interference after the discharge valve device is installed, so the flush water amount can be adjusted to a level appropriate to the type of toilet used.